# Resistance Estimate

Construction contracts often have stiff penalties if the vessel fails to meet design speed. The vessel’s profitability can hinge on making the correct speed at the correct power. To achieve this, you need a resistance estimate. The resistance estimate predicts the vessel resistance at various speeds. This requires consideration of multiple components.

- Wave making resistance
- Frictional resistance
- Appendage resistance
- Air resistance
- Wave interactions (multihulls only)

By isolating and each of the resistance components, DMS gains insight into the quality of your hull shape. We can determine which sets of physics dominate the vessel design and tell you where best to invest in further design optimization.

A typical vessel design requires several different rounds of resistance estimates. We begin with inexpensive methods. These offer lower accuracy but can update for new revisions in a few seconds. Towards the end of the design process, microscopic accuracy becomes paramount. In those cases, DMS offers detailed CFD analysis, or we can prepare plans for towing tank analysis. The key to success is a wide range of tools in our toolbox:

## Slender Body Theory Methods

- Michlet (Includes GODZILLA for genetic optimization of hullform)
- Maxsurf Resistance

## Parametric Methods

- Planing hulls
- Savitsky pre-planing
- Savitsky planing
- Blount and Fox
- Lahtiharju
- Wyman

- Displacement hulls
- Holtrop
- Compton
- Fun
- Van Oortmessen
- Series 60
- KR Barge Resistance

- Yachts
- Delft I, II
- Delft III

## Computational Fluid Dynamics

- Potential flow
- RANS VOF

## Towing Tank Test

- Subcontractor required

## Want to Learn More?

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